[Ibu menyusui memerlukan tambahan asupan zat gizi, terutama energi. Kementrian Kesehatan RI merekomendasikan penambahan sekitar 330 kkal saat menyusui. Penelitian ini bertujuan untuk mengetahui pengaruh asupan energi ibu menyusui terhadap keberhasilan menyusui. Desain penelitian yang digunakan adalah kohort prospektif (longitudinal) yang dilakukan pada 53 pasang ibu-bayi yang masih memberikan ASI predominan. Pemilihan responden dilakukan dengan purposive sampling pada bulan Maret—September 2014. Pengumpulan data dilakukan melalui wawancara dengan kuesioner, observasi, dan pengukuran status gizi (berat badan dan panjang badan). Hasil penelitian menunjukkan bahwa sebanyak 54,7% responden mendapat rata-rata asupan energi 2.100 kkal atau lebih. Uji Chi-square menunjukkan terdapat pengaruh yang bermakna rata-rata asupan energi ibu menyusui terhadap keberhasilan menyusui (RR=4,91)., The postpartum maternal needs incremental nutrition intake especially energy intake when she breastfeeds her baby. The ministry of health affairs suggests 330 kcal as additional energy is needed while mothers are breastfeeding. This research aims to understand the effect of postpartum maternal energy intake toward successful breastfeeding. The design of the research used prospective cohort (longitudinal) to 53 couples of breastfeeding mother-infant. Respondents of the research were selected by purposive sampling method from March to September 2014. Data were collected from interview by questionnaire, observation, and measurement of nutrition status (weight and height). The research results 54,7% of respondents posses 2100 kcal or more in average energy intake. Chi-square test indicates that there is a significant effect between the average of mother-breastfeeding energy intake and successful breastfeeding (RR=4,91).]